UBE2O remodels the proteome during terminal erythroid differentiation

During terminal differentiation, the global protein complement is remodeled, as epitomized by erythrocytes, whose cytosol is ~98% globin. The erythroid proteome undergoes a rapid transition at the reticulocyte stage; however, the mechanisms driving programmed elimination of preexisting cytosolic proteins are unclear. We found that a mutation in the murine Ube2o gene, which encodes a ubiquitin-conjugating enzyme induced during erythropoiesis, results in anemia. Proteomic analysis suggested that UBE2O is a broad-spectrum ubiquitinating enzyme that remodels the erythroid proteome. In particular, ribosome elimination, a hallmark of reticulocyte differentiation, was defective in Ube2o–/– mutants. UBE2O recognized ribosomal proteins and other substrates directly, targeting them to proteasomes for degradation. Thus, in reticulocytes, the induction of ubiquitinating factors may drive the transition from a complex to a simple proteome.

Source: ScienceNOW - August 3, 2017 Category: Science Authors: Nguyen, A. T., Prado, M. A., Schmidt, P. J., Sendamarai, A. K., Wilson-Grady, J. T., Min, M., Campagna, D. R., Tian, G., Shi, Y., Dederer, V., Kawan, M., Kuehnle, N., Paulo, J. A., Yao, Y., Weiss, M. J., Justice, M. J., Gygi, S. P., Fleming, M. D., Finley Tags: Biochemistry, Cell Biology, Online Only r-articles Source Type: news